The extracellular matrix (ECM) synthesis of OA chondrocytes partially depends on PLC-γ1 activation. OA chondrocytes were obtained from 16 patients with advanced OA. (A) Cultured cells were treated with or without U73122 (5 μM) for 3 h, and the protein expression levels of PLC-γ1, p-PLC-γ1, Sox-9, MMP-13, Col II, and AGG were detected by western blotting analysis using rat anti-PLC-γ1, p-PLC-γ1, Sox-9, MMP-13, Col II, AGG, and GAPDH antibodies; (B) Cultured cells were transfected with or without siRNA-PLC-γ1, and the protein expression levels of PLC-γ1, p-PLC-γ1, Sox-9, MMP-13, and TIMP1 were detected by western blotting using rat anti-PLC-γ1, p-PLC-γ1, Sox-9, MMP-13, TIMP1, and GAPDH antibodies. The values represent the mean ±S.E.M. of three to five independent experiments, each yielding similar results (*
p < 0.05, **
p < 0.01).